US1676051A - Tennis racket - Google Patents

Description

Jly, 1928. l R.. H. kFaoBlNscaN TENNIS RAC'KET orumawiled Dec. 15, 1923 Patented July 3, 1928.

UNITED STATES ROY E. ROBINSON, 0F CHICAGO, ILLINOIS.

TENNIS RACKET.

Application led December 15, 1923, Serial No. 680,956. Renewed September 8, 1927.

This invention relates to tennis rackets but more particularly to such as are provided with a metal frame and has for its primary -obj'ect to eliminate the cutting of the Stringing by the frame.

It has been found in practice that gut stringing cannot be used with metal frame rackets asnow produced because the metal quickly cuts the gut. These rackets have therefore been generally strung with Wire which does not possess the resiliency of gut, and even wire soon breaks. These frames are made of light gauge metal tubing which is punched for the Stringing and then bent into proper form. The punched holes are made as smooth as possible but the strings come in Contact with these edges and are cut thereby. This cutting is accelerated by the movement of the strings when the racket is in use.

In my improved racket the advantages of the metal frame are fully retained but the cutting of the Stringing is eliminated and gut may be used as well as in a woodenrame racket.

The many other objects and advantages of my invention will be better understood by reference to the following specification when considered in connection with the accompanying drawing illustrating certain selected embodiments thereon, in which Fig. 1 is a plan View of a racket.

Figs. 2 to 4 are transverse sections of the frame illustrating one method of construction.

Fig. 5 illustrates a further step in the formation of the racket frame.

Fig. 6 is a longitudinal section of a portion of' a complete frame.

F 1'gs 7 and 8 are transverse sections of modified forms of frame construction, and

Fig. 9 is a perspective view of a section of a modified form of frame.

Referring to the drawing and particularly Figs. 1 to 5, the racket comprises a frame 10, handle 11 and Stringing 12. The frame in the present embodiment comprises a tube 9 which is bent into substantially oval form, as at 13, with the ends of the tube turned outwardly, as at 14, and inserted into the handle. The portions 14 of the tube form what is ltermed the throat of the racket. A strut or spreader 15 is provided at the throat. This strut forms a portion of the frame to receive the Stringing. The particular design of racket frame illustrated in Fig. 1 is similar to that made by a wellknown manufacturer. The handle l11 is of wooden construction and a metal ferrule 16 envelops and supports the forward end thereof.

In my improved construction the metal tube 9 and the strut 15 are either completely or partially filled with a non-metal substance as at 18. A variety of substances may be used for this one which will not absorb moisture and consequently will not warp. A plastic molded mass such as vulcanized fiber thor- \oughly impregnated with a combination of phenol and formaldehyde, and then hardened by heating. Such material is plastic and has high compressive strength and relatively high tensile strength. `Very satisfactory results have been obtained by the use of leather, raw hide, or ordinary hard fiber and other substances of a similar character. This filled tube may be manufactured in a variety of different ways, one of which is illustrated in Figs. 2 to 4 inclusive. By this method the filler material 18 is driven into the round tube 9 as in. Fig. 2. The filled tube is then punched for the stringing. In the first punching operation a series of oppositely disposed relatively large holes 19 are punched in the metal shell without materially penetrating the filler, but partially penetrating the same, as in Fig. 3. This causes the tube to assume a somewhat oval cross-section. The inwardl -turned edge 2O produced by the punching 1s forced into the filler and thus becomes permanently embedded therein. The next ste is to drill or otherwise drive a seria o relatively small holes 21 through the filler, these holes 21 being substantiall concentric with the corresponding large oles 19 in the metal tube (Figs. 4 to 6). The edges of the small holes 21 are preferably slightly rounded or chamfered to provide a rounded bearing surface for the strings. The punched tube may then be assed between compressing rolls as 17 to fiirther flatten the same as 1s illustrated in Fig. 5. This is advantageous as it tends to further force the punch-hole edges into the filler. This step can either precede or follow the drilling of the filler. The small holes in the filler may obviously be provided before it is inserted in the metal tubing and this is perferable where the filler is composed of hard fiber.

In Fig. 7 is illustrated a frame which is purpose but I prefer rectangular in cross-section instead of round or oval. This is punched or slotted in the same manner as the round or oval tube.

Instead of inserting the filler in the unpunched tube and then punching the tube in the manner described, the tube may be punched and the vfiller subsequently inserted. This is accomplished by usingv a filler of a thickness to permit it to be pushed into the tube between the protruding edges of the punched holes. The tube may then be compressed by means of rollers to cause the edges to be embedded in the filler. Such a construction is illustrated in F ig. 8 of vthe drawing, the metal tube being designated 25 and the filler 26.

In Fig. 9 of the drawing is illustrated a modified form of frame construction which primarily consists of a metal shell vas 80 and a filler as 31. This shell is not in tubular form but is made by bending a strip of sheet metal in the form indicated with the edges 32 of the strip turned inwardly and fitting within corresponding slits or grooves 83 in the previously formed filler. In this construction a reinforcing plate, as 34, may be interposed between the top or outer wall 35 of the shell and the corresponding wall of the filler. The strip and reinforcement are preferably provided with a series of perforations or slots, as 36 and 37, before being bent. The filler is perforated forthe stringing as at 38, these perforations being considerably smaller than the corresponding perforations 36 and 87 inthe shell and reinforcement.

It will be evident from the foregoing description that the Stringing in my improved socket is held away at all times from 'metal edges by the filler and can not be eut thereby. The metal bearing surfaces are smooth and rounded. The metal tube or shell may be made of thinl steel, aluminum alloy, nickel, or any other material possessing the necessary strength and lightness.

'I am aware that the frame construction may be materially varied without departing from the spirit of my invention and I reserve the right to make all such variations as fairly fall within the scope of the following claims.

I claim yas my invention:

1. In a tennis racket, a frame comprising a tubular metal shell having a series ofoppositely disposed perforations therein to receive Stringing, and string Guides of nonmetallic material within said shell, said string guides projecting into said perforations to prevent the strings from contacting with the edges at said perforations in said metal shell.

2. In a tennis racket, a frame comprising a metal shell having a series of oppositely disposed perforations therein to receive Stringing, and Stringing guides of non-meaevaoei metallic material Within said shell having string passages connecting the corresponding perforations in said shell, said passages being substantially concentric with said perforations and of smaller cross-sectional area, said string guides projecting into said perforations whereby the strings are prevented from contacting with the edges of the metal at said perforations.

4. In a tennis racket, aframe comprising a tubular metal shell having a series of oppositely disposed perforations therein to receive Stringing, and string guides of fibrous material within said shell, said fibrous material projecting into said perforations whereby the strings are prevented from contacting with the edges of the metal at said perforations.

5. In a tennis racket, a frame comprising a metal shell having Stringing holes formed therein, and a strip of non-metallic material extending longitudinally within said shell, the turned-in metal edges of the shell produced by the forming of the holes therein being partially embedded in said strip.

6. In a tennis racket, a frame comprising a metal shell having relatively large stringing holes formed therein, and a strip of nonmetallic material extending longitudinally within said shell and provided with stringing passages communicating with the corresponding holes in said shell and of smaller cross-sectional area than said holes, the edges of the holes being formed with turnedin portions embedded in said strip.

7. In a tennis racket, a frame comprising a metal shell having. Stringing holes punched therein, and a fibrous filler extending longitudinally within said shell and having stringing passages connecting the corresponding holes in said shell, the turned-in metal edges of the shell produced by the punching of said holes being partially embedded in said filler.

8. In a tennis racket, a frame comprising a thin metal shell having Stringing perforations therein, and filler of non-metallic material within said shell provided with stringing perforations communicating with the corresponding perforations in said shell, the material of the filler projecting into perforations in the shell.

9. In a racket, a frame comprising a tubular metal shell, a cushioning filler Within the shell, there being Stringing passages extending through said yshell and filler, and strings passing therethrough, the edges of the shell at the passages being in contact with the filler to prevent exposure and contact thereof With the strings except at the filler to4 thereby prevent cutting of the strings.

l 10. In a racket, a frame comprising a tubular metal shell, a moisture proof filler Within said shell, stringing passages extending through said shell and filler and strings passing therethrough, the edges ot the metal at the passages in the shell being rounded to dispose the strings out of contact with the edges and prevent cutting of the strings thereby.

1l. In a racket, a frame comprising a tubular metal shell, a moisture-proof ller Within said shell, Stringing passages extending through said shell and filler and strings passing therethrough, the passages in the shell being formed With inturned edges,

and said edges being embedded lin said filler to prevent cutting of the strings thereby.

12. In a racket, a frame portion having a stringing hole with a non-metallic stringcontacting portion and an easy bearing face approaching the non-metallic string-contacting portion and being free of sharp edges.

13. In a racket, a string support having a Stringing hole With a non-metallic string contacting portion combined With a metallic easy bearing face approaching the nonmetallic stringcontacting portion.

14. In a tennis racket` a frame comprising a tubular metal shell and a non-moisture absorbing iller Within said shell which consists of plastic material of high compressive strength and relatively high tensile strength.

15. In a racket, a frame comprising a tubular shell, a moisture-proof iller; Within said shell, there being Stringing passages extending through said shell and filler and strings passing therethrough, the edges of the shell at the passages being rounded and turned outwardly at their inner ends to dispose the strings out of contact with the shell and prevent cutting of the strings thereby.

16. In a racket, a frame comprising a tubular metal shell, a filler of high compressive strength and relatively high tensile strength Within said shell, there being Stringing passages extending through the shell and iller and strings passing therethrough, the edges of the metal at the passages in the shell being rounded and enlarged with respect to the passages of the filler which receive the strings to dispose them out of contact with the metal and prevent cutting of the strings thereby.

17. In a racket, a. frame comprising a shell, a cushioning and vibration-absorbing filler Within the shell, there being Stringing passages extending through the shell and filler, and strings passing therethrough, the edges of the shell at the passages being Covered by the filler and the passages of the filler being restricted to prevent Contact 0f the strings with the edges of the shell at the passages therein and cutting of the strings thereat.

18. In a racket, a frame comprising a tubular metal shell, a non-metallic cushioning and vibration absorbing or dampening filler Within the shell, the edges of the shell at the passages engaging the liller around its passages to prevent cutting of the strings.

19. In a tennis racket, a frame comprising a tubular metal shell, a strip of nonmetallic cushioning and vibration dampening material extending longitudinally within said shell and substantially filling the same, and Stringing passages extending through said shell and said strip and disposed to hold the strings out of contact with the shell or edges thereof at the passages.

20. In a tennis racket, a frame comprising a metal shell, a strip of non-metallic cushioning and vibration dampening material extending longitudinally Within said shell, and stringing passages extending through said shell and said strip, the material of the shell being turned in at the passages to contact with the strip so that the strings contact only with the strip in the passages and prevent contact of the strings with the edges of the metal shell at the passages.

21. A racket frame having a metal exterior facing secured to or joined With a filler member, with inturned edges projecting into said filler.

22. A racket frame having a metal exterior face secured to a filler member, with inturned portions projecting into said filler, the filler having openings for receiving Stringing and t-he face having edge portions protected by the ller Where the strings extend therethrough.

23. A metal racket frame having an inner and an outer face of metal with a nonmetallic filler held rigidly between said metal faces, Stringing holes formed in the metal faces, and non-metallic filler in said holes.

24. A metal racket frame having an inner and an outer face of met-al with a nonmetallic liller held rigidly between said metal faces, and Stringing holes formed in the metal faces, the edges of the metal at the holes being pressed against the filler to protect the same from contact of the edges of the metal with the Stringing at the holes.

25. In a tennis racket, a frame comprising a tubular shell and Stringing passages extending through said shell, the passages having cushioning guides extending up into perforations or passages of the shell.

26. A metal tennis racket frame with Stringing holes of a substantial depth formed therein and non-metallic material so disposed in relation to the Stringing holes as to prevent strings contacting with any cutting edges of the metal holes regardless of what angle the strings take in passing out of the holes, and the frame having an easy bearing face Wherever contacting with the Stringing.

27. A metal tennis racket frame combined with a non-metallic cushioning member, both having -stringing holes, strings passing through the Stringing holes formed in both, the Stringing holes in the non-metallic member being smaller than the corresponding ones in the metal frame, and the holes in the metal frame being rounded or `chamfered and margined back from the non-metallic holes.

28. A tennis racket having a metal frame combined with a non-metallic member and Stringing passing through said frame and non-metallic member and so disposed as to bear against the non-metallic member without contacting with any cutting edges of the sti-inging holes of the metal frame and to contact with an easy bearing face of the metal.

29. In a. tennis racket frame formed of a metal shell and a non-metallic vmaterial within, the non-metallic material being held in place by turned-in edges of the metal at i the Stringing holes formed in a face of the shell. f

30. A metallic tennis racket frame having a tubular cross section with interior shock absorbing material, the shock absorbing material being held in position by turned-in edges of stringing holes formed in the tube.

31. A tennis racket frame having stringing and a metal outer Wall transverse to the plane of the Stringing, a non-metallic element bearing on the lnner face of said wall,

the Stringing contacting with the metal on the outer face of said metal wall and bearing against the non-metallic element, the non-metallic element protecting the strings from'any cutting edges of the metal Wall.

32. A tennis racket frame having stringing holes and Stringing passing through lthe same and a metal outer Wall transverse to the plane of the Stringing, a non-metallic clement bearing on the inner face of said wall, the Stringing contacting with the metal on the outer face of said metal Wall and bearing against the non-metallic element, the non-metallic element protecting the strings from any cutting edges of the metal Wall, and a non-metallic cushioning element also in the holes of the metal Wall.

33. A tennis racket comprising a tubular frame' having Stringing holes in oppositev Walls and string cushioning material Within the tube and the tubebeing crushed against the cushioning material.

34. A tennis racket comprising va shell having Stringing holes with turned-in edges and a Filling material between said turnedin edges.

35. A tennis racket having a frame formed of a shell with Stringing holes formed in the shell thereof and a non-string cutting material within the shell covering the cutting edges of the shell at the holes.

36. In a tennis racket, a metallic frame having Stringing passages in same and the passages having non-metallic cushioning guides therein to receive .the Stringing and forming non-abraiding and non-cutting bearings therefor.

ROY H. ROBINSON.

Images